Can Microbes Affect Your Mood? When Gut Bacteria Feed on Brain Chemicals

Scientists have learned of a type of gut bacteria that may be a "depression microbe" linked to mood disorders in people. New Scientist reported on the finding by researchers at the Lewis Lab in Northeastern University in Boston, noting that this was the first time gut bacteria have been observed to consume brain chemicals.

The lab team, led by microbiologist Philip Strandwitz, gave a presentation of their work at ASM Microbe, the 2016 general meeting of the American Society For Microbiology. Their research revealed that recently discovered gut bacteria, designated KLE1738, could be grown only on γ-Aminobutyric acid (GABA), a neurotransmitter that can counteract the overstimulation of nerve cells.

The organic molecule known as GABA works to inhibit overly excited neurons, producing a calming effect. GABA can help stabilize a mind affected by conditions such as anxiety or depression. Current scientific research finds a link between having a low plasma level of GABA and being prone to schizophrenia, depression, anxiety and sleep disorders, according to Everyday Health.

Strandwitz's team did a genomic analysis of the KLE1738 microbe which showed that its metabolism depended on GABA alone. Noting that it exists alongside other forms of gut bacteria that produce large amounts of GABA, the team concluded that gut flora play a key role in modulating the body's GABA levels.

This implies that the composition of our gut microbiome may have a significant influence on our emotional states and mood conditions. Strandwitz put forward a vision of mental health therapists adjusting the population of a patient's microbiome in helping them to overcome their disorders.